Various sand control methods by gravel packing outside of down-hole screens are known in the art. Gravels are introduced from the surface to fill the annular space between outside the screen and the inner wall surface of a wellbore to prevent the production of undesirable solids from the formation. More recently, it was thought that the need for gravel packing could be eliminated if a screen or screens could be expandable to the inner wall surface of a wellbore. Problems arose with the screen expansion technique as a replacement for gravel packing because of wellbore shape irregularities. U.S. Pat. No. 7,013,979 disclosed a totally conforming expandable screen to conform the borehole irregular shape. This conforming expandable screen consists of a self-swelling material that is capable of expansion of its volume by contacting well fluids. U.S. Pat. No. 7,318,481 disclosed a self-conforming expandable screen which comprises of thermosetting open cell shape-memory polymeric foam. The foam material composition is formulated to achieve the desired transition temperature slightly below the anticipated downhole temperature at the depth at which the assembly will be used. This causes the conforming foam to expand at the temperature found at the desired depth, and to remain expanded against the borehole wall.
There are many types of polymeric foam commercially available such as natural rubber foam, vinyl rubber foam, polyethylene foam, neoprene rubber foam, silicone rubber foam, polyurethane foam, VITON® rubber foam, polyimide foam, etc. Most of these foams are cell-closed, soft and lack of structural strength to be used in the downhole conditions. Some of these foams such as rigid polyurethane foam are hard but very brittle. In addition, conventional polyurethane foams which are generally made from polyethers or polyesters lack thermal stability and the necessary chemical capabilities. Consequently these foams are undesirably quickly destroyed in the downhole fluids, especially at an elevated temperature.
It would thus be very desirable and important to discover a method and device for deploying an element at a particular location downhole to prevent the production of undesirable solids from the formation and allow only the desired hydrocarbon fluids to flow through.